The invention is generally directed to a holder for an electrical safety fuse. More specifically, the present invention relates to such a holder for a cylindrical fuse having contact caps at its ends that are resiliently clamped between a closure cap at one end and a coil compression spring at the opposite end inside of a tubular housing.
Generally, fuse holders are known in which the fuse is accessed by a twist-off removable closure cap. The closure cap has a conductive portion which electrically contacts an end of the fuse. This contact portion has a contact tab which engages a contact pin to form an electrical outlet connection. Known fuse holders also have a compression spring within the tubular housing to bias against the fuse. The compression spring is connected to a terminal pin that projects from the holder to connect to an incoming line. When assembling such a fuse holder, the closure cap is pressed downward against the compression spring force, then rotated to cause the contact tab to slide into a slot in the manner of a bayonet-type closure.
In conventional fuse holders, there is a risk, however, that the contact tab will lift off from an associated recess in the cap, for example, by inadvertent pressure on the closure cap, resulting in an interruption of the current flowing across the fuse. Another problem with prior art holders is that portion of the contact pin which engages the contact tab can torsionally deflect in an undesirable manner, decreasing the integrity of electrical contact with the tab.
For simplifying the structural outlay and for eliminating these problems, it has been proposed to provide the contact pin with two tangentially extending clamp legs at its front side, these forming a rigid clamp slot for the contact tab that is turned thereinto. Due to tolerance in the width of the clamp slot and in the thickness of the contact tab, one must thereby count on too great a scatter in the clamping power. There is thus the risk that the contact tab is introduced with play relative to the clamp legs or that the clamping power is so high that damage occurs, rendering free introduction impossible.